/*      $OpenBSD: poll.c,v 1.6 2016/09/20 17:25:06 otto Exp $   */
/* David Leonard <d@openbsd.org>, 2001. Public Domain. */

#include <pthread.h>
#include <fcntl.h>
#include <poll.h>
#include <paths.h>
#include <unistd.h>
#include <stdlib.h>
#include <util.h>
#include "test.h"


#define POLLALL (POLLIN|POLLOUT|POLLERR|POLLNVAL)

static void
print_pollfd(struct pollfd *p)
{

        printf("{fd=%d, events=< %s%s%s> revents=< %s%s%s%s%s>}",
                p->fd,
                p->events & POLLIN ? "in " : "",
                p->events & POLLOUT ? "out " : "",
                p->events & ~(POLLIN|POLLOUT) ? "XXX " : "",
                p->revents & POLLIN ? "in " : "",
                p->revents & POLLOUT ? "out " : "",
                p->revents & POLLERR ? "err " : "",
                p->revents & POLLHUP ? "hup " : "",
                p->revents & POLLNVAL ? "nval " : ""
        );
}

static void *
writer(void *arg)
{
        int fd = *(int *)arg;
        const char msg[1] = { '!' };

        ASSERTe(write(fd, &msg, sizeof msg), == sizeof msg);
        return NULL;
}

static void *
reader(void *arg)
{
        int fd = *(int *)arg;
        char buf[1];

        ASSERTe(read(fd, &buf, sizeof buf), == sizeof buf);
        return NULL;
}

int
main(int argc, char *argv[])
{
        pthread_t t;
        void *result;
        int null, zero, tty, dummy;
        int tube[2];
        struct pollfd p[3];

        /* Try an empty poll set */
        ASSERTe(poll(NULL, 0, 0), == 0);

        CHECKe(zero = open(_PATH_DEV "zero", O_RDONLY));
        CHECKe(null = open(_PATH_DEV "null", O_WRONLY));
        CHECKe(openpty(&dummy, &tty, NULL, NULL, NULL));

        /* Try both descriptors being ready */
        p[0].fd = zero;
        p[0].events = POLLIN|POLLOUT;
        p[0].revents = 0;
        p[1].fd = null;
        p[1].events = POLLIN|POLLOUT;
        p[1].revents = 0;

        ASSERTe(poll(p, 2, 0), == 2);   /* if 4 then bug in kernel not fixed */
        printf("zero p[0]="); print_pollfd(&p[0]); putchar('\n');
        printf("null p[1]="); print_pollfd(&p[1]); putchar('\n');
        ASSERT((p[0].revents & POLLIN) == POLLIN);
        ASSERT((p[1].revents & POLLOUT) == POLLOUT);

        /*
         * Try one of the descriptors being invalid
         * and the other ready
         */
        printf("closing zero\n");
        close(zero);

        p[0].fd = zero;
        p[0].events = POLLIN|POLLOUT;
        p[1].fd = null;
        p[1].events = POLLIN|POLLOUT;
        ASSERTe(poll(p, 2, 0), == 2);   /* again, old kernels had this bug */
        printf("zero p[0]="); print_pollfd(&p[0]); putchar('\n');
        printf("null p[1]="); print_pollfd(&p[1]); putchar('\n');
        ASSERT((p[0].revents & POLLNVAL) == POLLNVAL);
        ASSERT((p[1].revents & POLLOUT) == POLLOUT);

        printf("closing null\n");
        close(null);

        /* 
         * New pipes. the write end should be writable (buffered)
         */
        CHECKe(pipe(tube));
        CHECKe(fcntl(tube[0], F_SETFL, O_NONBLOCK));
        CHECKe(fcntl(tube[1], F_SETFL, O_NONBLOCK));

        p[0].fd = tube[0];
        p[0].events = POLLIN;
        p[1].fd = tube[1]; 
        p[1].events = POLLOUT;
        ASSERTe(poll(p, 2, 0), == 1);
        printf("rpipe p[0]="); print_pollfd(&p[0]); putchar('\n');
        printf("wpipe p[1]="); print_pollfd(&p[1]); putchar('\n');
        ASSERT(p[0].revents == 0);
        ASSERT(p[1].revents == POLLOUT);

        /* Start a writing thread to the write end [1] */
        printf("bg writing to wpipe\n");
        CHECKr(pthread_create(&t, NULL, writer, (void *)&tube[1]));
        /* The read end [0] should soon be ready for read (POLLIN) */
        p[0].fd = tube[0];
        p[0].events = POLLIN;
        ASSERTe(poll(p, 1, INFTIM), == 1);
        printf("rpipe p[0]="); print_pollfd(&p[0]); putchar('\n');
        ASSERT(p[0].revents == POLLIN);
        reader((void *)&tube[0]);       /* consume */
        CHECKr(pthread_join(t, &result));

        SUCCEED;
}